Polyvinylbutyral is widely used in combination with one or more layers of glass to provide a composite which is resistant to shattering. The polyvinylbutyral typically contains a plasticizer to provide a balance of mechanical properties satisfactory for subsequent handling and performance requirements.
Particularly in automotive applications, the polyvinylbutyral also contains an adhesion control additive to provide a balance between maintaining the integrity of a windshield on impact and cushioning impact through energy absorption. Many adhesion control additives have been used successfully in the past, but often exhibit a moisture sensitivity that can result in a clouding of the polyvinylbutyral sheeting in high humidity environments, particularly at the edges of glass laminates containing the sheeting.